Metal complexes of n,n-dialkylesters of ethylenedinitrilotetraacetic acid and and compositions stabilized thereby

ABSTRACT

SYNTHETIC POLYMERIC COMPOSITIONS WHICH ARE SUBJECT TO ULTRAVIOLET LIGHT DETERIORATION ARE STABILIZED BY MEANS OF AN EFFECTIVE AMOUNT OF A METAL COMPLEX OOF N,N&#39;&#39;-ALKYL ESTERS OF ETHYLENEDINITRIOTETRAACETIC ACID. POLYMERIC COMPOSITIONS CONTAINING THESE STABILIZERS ALSO EXHIBIT AND INCREASE IN SUSCEPTIBILITY TO DYE AS COMPARED TO THE UNSTABILIZED POLYMERIC COMPOSITIONS. A TYPICAL EMBODIMENT IS THE NICKEL COMPLEX, N,N&#39;&#39;-DI-N-OCTADECYL ESTER OF ETHYLENEDINITRILOTETRAACETIC ACID.

United States Patent O METAL COMPLEXES OF N,N-DIALKYLESTERS F ETHY LENEDIN ITRILOTETRAACETIC ACID AND AND COMPOSITIONS STABILIZED THEREBY JohnD. Spivack, Spring Valley, N.Y., assignor to Ciba- Geigy Corporation,Greenburgh, N.Y. No Drawing. Filed Aug. 30, 1971, Ser. No. 176,307 Int.Cl. C07f 15/04, 11/00, 13/00 US. Cl. 260439 R 4 Claims ABSTRACT OF THEDISCLOSURE DETAILED DISCLOSURE The present invention relates to novelmetal derivatives of N,N'-dialkyl esters of ethylenedinitrilotetraacetic acid and the use thereof in the preparation of syntheticpolymeric compositions of increased stability to ultraviolet (UV) lightand increased susceptibility to dye.

More specifically, this invention relates to a compound of the formula:

R Og CHFI I OHZ O n (1) wherein R is an alkyl group of from 1 to 22carbon atoms; M is selected from the group consisting of zinc,manganese, nickel, cobalt, chromium, copper, aluminum, titanium andiron, and n has a value of from 1 to 4, the value of n being the same asthe available valence of M.

By the term alkyl is intended a branched or straight chain saturatedhydrocarbon group having from 1 to 22 carbon atoms. Typical of suchalkyl groups are methyl, ethyl, propyl, isopropyl, butyl, t-butyl,pentyl, isopentyl, hexyl, octyl, dodecyl, tetradecyl, hexadecyl,octadecyl, eicosyl, docosyl and the like.

The group n consists of a metal cation such as the cation form oflithium, sodium, potassium, barium, cal cium, aluminum, titanium, tin,vanadium, antimony, chromium, molybdenum, manganese, iron, cobalt,copper and the like, that is, a metal having an atomic number of up to6. The preferred metal cations are zinc, manganese, nickel, cobalt,chromium, copper, aluminum, titanium and iron. The most preferred isnickel.

This invention also relates to compositions of matter which arestabilized against ultraviolet deterioration which comprises a syntheticorganic polymer normally subject to ultraviolet deterioration containingfrom about 0.05% to by weight of the polymer of the compounds of Formula1 and preferably from 0.2% to 5% by weight.

The compounds of the present invention also render synthetic polymericsubstances, such as the polya-olefins of the polyethylene andpolypropylene type, more amenable to dyeing and also reduce the tendencyof the polymeric substance to discolor and embrittle upon exposure tolight, whether dyed or not. These compounds may be incorporated in thepolymeric substance during the usual processing operations, for exampleby hot milling, the

composition then being extruded, pressed, blow molded or the like intofilms, fibers, filaments, hollow shapes and the like. Moreover,polymeric compositions containing these novel salts may be dyed, eitherdirectly after incorporation of the salt or after further processing,such as the formation of yarns or fabrics. The polymer is stabilized bythe presence of these metal salts both before and after dyeing so thatthe coloring step need not follow directly. Once dyed, the coloredcompositions exhibit fastness to light and to solvents, propertiespreferred in washing, dry cleaning and general use.

The conditions of the dyeing will of course vary with the particular dyeemployed. Generally the nature of the dye is not restricted and any ofthe many known metal chelating dyes may be employed, as for example, theorange dye of the formula:

It is also to be understood that the effect obtained with a particulardye can be altered by variation of the particular metal cation of thesecompounds and by the amount of these compounds present in the polymer,although generally from about 0.05 to 10% preferably 0.1 to 5% byweight, is employed.

While polypropylene has been herein mentioned specifically, thesecompounds are useful in numerous other substances whose regular andinert polymeric structures tend to resist dyes and are subject to UVdeterioration. Materials for which the compounds of the presentinvention are useful thus include synthetic organic polymerissubstances, both homopolymeric and copolymeric, such as vinyl resinsformed from the polymerization of vinyl halides or from thecopolymerization of vinyl halides with unsaturated polymerizablecompounds, e.g., vinyl ester, a,fi-unsaturated acids, a,B-unsaturatedesters, refiunsaturated ketones, a,fiunsaturated aldehydes andunsaturated hydrocarbons such as butadienes and styrene; poly-a-olefinssuch as polyethylene, polypropylene, polybutylene, polyisoprene and thelike, including copolymers of poly-a-olefins; polyurethanes such as areprepared from polyols and organic polyisocyanates; polyamides, such aspolyhexamethylene adipamide; polyesters such as polymethyleneterephthalates; polycarbonates; polyacetals; polystyrene;polyethyleneoxide; polyacrylics such as polyacrylonitrile; and the like,including mixtures of the foregoing such as those of high impactpolystyrene containing copolymers of butadiene and styrene and thoseformed by the copolymerization of acrylonitrile, butadiene and/ orstyrene. The compounds of this invention may be used for stabilizing theabove materials even when dyeing is not anticipated.

Other materials which while not generally dyed, are neverthelessstabilized against UV deterioration by the compounds of the presentinvention include lubricating oil of the aliphatic ester type, e.g.,di-(Z-ethylhexyl) azelate, pentaerythritol tetracaproate and the like;animal and vegetable derived oils, e.g., linseed oil, fat, tallow, lard,peanut oil, cod liver oil, castor oil, palm oil, cotton seed oil and thelike; hydrocarbon material such as gasoline, both natural and synthetic,diesel oil, mineral oil, fuel oil, cutting fluids, waxes, resins and thelike; fatty acids; varnishes, soaps; and the like.

The stabilizers employed in this invention can be also used incombination with other stabilizers or additives. There may also bepresent compounds which help to improve the heat and oxidative stabilityof polymers such as phenolic compounds which inactivate free radicals,by hydrogen atom donation, as well as, compounds capable of decomposingperoxides such as dilaurylthiodipropionate. The stabilizers may also beused in combination with other additives such as UV light absorbers,anti-acids such as calcium soaps, phosphates, anti-static agents, andthe like. Other materials which may also be incorporated into thepolymer composition include for example, pigments, dyes, fillers, etc.

The stabilized polymers of the present invention have utility in thenormal uses for which plastics are employed and are particularly usefulfor film, coatings and fiber.

The compounds of the present invention per se, can be prepared bytreating the appropriate dialkyl ester of ethylenedinitrilotetraaceticacid with the reactive form of the metal or complex, e.g., sodiumhydroxide, lithium hydroxide, potassium hydroxide or the like.Alternatively, and preferably in the case of metal complexes and metalsother than alkali metals, a double decomposition is employed. Thus, forexample, a sodium salt of the present invention is treated with nickelchloride. In a similar fashion, use of other halides such as aluminumchloride, barium chloride and the like results in formation of thecorresponding metal derivative.

The preparation of the N,N'-dialkyl esters ofethylenedinitrilotetraacetic acid that are used as starting materials inpreparing the compounds of this invention are described in US. Pat. No.3,497,535. The N,N-dialkyl esters of ethylenedinitrilotetraacetic acid,can conveniently be prepared by the reaction ofethylenedinitrilotetraacetic acid dianhydride and suitable alcohols.

The following examples, presented for illustration and not limitation,will serve to typify the nature of the present invention.

EXAMPLE 1 Nickel complex of N,N'-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid A solution of 11.16 grams of thedi-n-octadecyl ester of ethylenedinitrilo tetraacetic acid (0.014 mole)in 1 liter of isopropanol was converted to a solution of the dipotassiumsalt by the addition of 28.0 ml. of 1 normal methanolic potassiumhydroxide. To this solution was added 3.32 grams of nickel chloridehexahydrate (0.014 mole) at a temperature of 10 C. The turbid reactionmixture was stirred at 23 to 25 C. for 2 /2 hours and at 50 C. for 20minutes. The reaction mixture was then clarified by filtration, theclear filtrate being concentrated by distillation at 45 C. and 15 mm.mercury. The isolated residue was dissolved in 100 ml. of benzene,filtered, and the residue isolated by distillation of the solvent at4045 C. at a pressure of 0.10 mm. Hg for 3 hours.

Analysis.-Calcd.: nickel, 6.88%. Found: nickel,

EXAMPLE 2 6.45

By following the procedure of Example 1 and substituting the followingmetal complexes for nickel chloride,

(a) Manganese chloride (b) Zinc chloride Cobalt chloride ((1) Chromiumchloride (e) Copper chloride (f) Aluminum chloride (g) Titanium chloride(h) Ferric chloride There are thus respectively obtained:

(a) Manganese complex of N,N-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(b) Zinc complex of N,N'-di-n-octadecy1 ester ofethylenedinitrilotetraacetic acid.

(c) Cobalt complex of N,N-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(d) Chromium complex of N,N'-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(e) Copper complex of N,N-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(f) Aluminum complex of N,N'-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(g) Titanium complex of N,N'-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid.

(h) Iron complex of N,N-di-n-octadecy1 ester ofethylenedinitrolotetraacetic acid.

EXAMPLE 3 By following the procedure of Example 1 and substituting thefollowing dialkyl esters of ethylenedinitrilotetraacetic acid:

(a) N,N-dimethyl ester of ethylenedinitrilotetraacetic acid (b)N,N'-dibutyl ester of ethylenedinitrilotetraacetic acid (c)N,N'-di-n-dodecyl ester of ethylenedinitrilotetraacetic acid there arethus respectively obtained:

(a) Nickel complex of N,N'-dimethyl ester ofethylenedinitrilotetraacetic acid (b) Nickel complex of N,N'-di-n-buty1ester of ethylenedinitrilotetraacetic acid (c) Nickel complex ofN,N'-di-n-dodecyl ester of ethylenedinitrilotetraacetic acid.

EXAMPLE 4.--LIGHT STABILIZATION TESTS (A) Outdoor exposure tests (a)Sample preparation: 5 mil oriented monofilaments.The nickel complex ofdi-n-octadecyl ester of ethylenedinitrilo tetraacetic acid was dissolvedin distilled methylene chloride and blended with polypropylene (HerculesProfax 6501) in a Hobart mixer. A buffer (such as calcium stearate) andantioxidant (di-octadecyl (3,5-di-tbutyl-4-hydroxybenzyl) phosphonate)were added to the polymer blend. To facilitate moisture removal allblends are vacuum dried shortly before extrusion. Samples were alsoprepared containing the additional UV stabilizer (2- (3,5-di-t-butyl--hydroxyphenyl)-5'-chlorobenzotriazole.

Samples were processed as follows:

(1) Compounding and pelletizing:

1" extruder: L/D=20/l at 40 r.p.m. Melt temperature: 450 F.

(2) Monofilament:

Melt temperature: 500 F. 1" extruder: L/D=24/1 at 20 r.p.m. Spinnerette:1 hole, 20 mil diameter/ hole Air cooling was accomplished by spinninginto a cooling tower 6' x 6 x 5" fitted with a fan delivering 65 c.f.m.of an.

(3) Filament take-up: The cooled monafilament was wound on Godet rollsat a filament speed of 500 ft./ min. (4) Orientation:

Godet temperature: 257 F. Orientation ratio: 4:1

(b) Test method for weathering stability.-The monofilament was exposed45 south direct in Florida. Tensile measurements were performed at eachexposure interval with the Instron Model TM.

The results indicated below show the number of kilolangleys (kL) to 50%retention of tensile strength. A Langley is a measure of energy in theultraviolet region to which the samples have been exposed.

Kl. to 50% retention Formulation: of tensile strength (a) 0.5% nickelcomplex of N,N'-di-n-octadecyl ester of ethylenedinitrilotetraaceticacid; 0.2% di-octadecyl (3,5 di-t-butyl-4-hydroxybenzyl) phosphonate;0.1% calcium stearate 63 Kl. to 50% retention Formulation: of tensilestrength (b) 0.5% nickel complex of N,N'-di-n-octadecyl ester ofethylenedinitrilotetraacetic acid; 0.5% 2(3,5-di-t-bntyl-2'-hydroxyphenyl)-5'-chlorobenzotn'azole; 0.2%di-octadecyl(3,5-di-t-butyl- 4-hydroxybenzyl) phosphonate; 0.1% calciumstearate 160 (c) 0.2% di-octadecyl(3,5 di-t-butyl-4-hydroxybenzyl)phosphonate; 0.1% calcium stearate 34 Improved stabilization ofpolypropylene to UV light is also obtained when the zinc, manganese,nickel, cobalt, chromium, copper, aluminum, titanium, and ironcornplexes of di-n-octadecyl ester of ethylenedinitrilo tetraacetic acidis substituted in each case for the above mentioned nickel complex.

(B) Artificial light exposure test Deterioration of most polymers causedby ultraviolet light is so slow at ambient temperatures, even in theabsence of stabilizers, that testing of the etfects of stabilizersgenerally must be conducted either at higher temperatures or in anaccelerated artificial light exposure device in order to yield resultsin a convenient period of time. The tests conducted on polymers using anartificial light exposure device is described below:

(a) Sample preparation: 25 mil plaques.Unstabilized polypropylene powder(Hercules Profax 6501) is thoroughly blended with the indicated amountsof additives. The blended material is then milled on a two roll mill for5 minutes at 182. The milled sheet is then compression molded at 220 C.into 25 mil thick plaques under a pressure of 175 p.s.i. and watercooled in the press.

(b) Testing method: This test is conducted in a FS/BL unit, basically ofthe American Cyanamid design, which consists of 40 tubes of alternatingfluorescent sun lamps and black lights of each). The mil sample plaqueswhich are mounted on white cardboard stock are placed on a rotating drum2 inches from the bulbs. The plaques are exposed in the FS/BL unit untilthey become sutliciently brittle to break cleanly when bent 180. Theresults are recorded as hours of exposure to embrittlement.

The test results reported below were obtained according to theprocedures described above. The amounts of the additives are expressedin Weight percent based on the weight of the polymer.

Formulation: Hours to brittleness (a) 0.5% nickel complex ofN,N'-di-n-octadecyl ester of ethylenedinitrilotetraacetic acid (Ex. 1);0.1% of di-octadecyl (3,5-di-t-butyl-4-hydroxybenzyl) phosphonate(di-octadecyl) 110 3,5di-t-butyI-4-hydroxybenzy1) phosphate is anantioxident which aids in processing the polymer.

When compared to a sample of unstabilized polypropylene tested accordingto this same procedure the stabilized sample containing the nickelcomplex was significantly more stable.

Improved stabilization of polypropylene is obtained when the nickelcomplex of dimethyl, dibutyl and di-ndodecyl esters of ethylenedinitrilo tetraacetic acid is used in place of the nickel complex of thedi-n-octadecyl ester.

6 EXAMPLE 5 Nickel complexes of the dimethyl, di-n-dodecyl anddi-n-octadecyl esters of ethylenedinitrilotetraacetic acid areseparately incorporated into polypropylene at a concentration providinga nickel concentration of 0.12%. The samples are then dyed with PolyOrange RM, Poly Dark Blue 213M and Poly Brilliant Yellow GM. All thesamples dye well with all the above dyes.

EXAMPLE 6 A composition comprising acrylonitrile-butadienestyreneterpolymer and 1% by weight of the nickel complex of di-n-octadecylester of ethylenedinitrilotetraacetic acid resists embrittlement due toUV deterioration longer than one which does not contain the stabilizer.

A composition comprising polyurethane and 1.0% by weight of the tincomplex of di-n-dodecyl ester of ethylenedinitrilo tetraacetic acid ismore stable under fluorescent sunlamps, black lights and fluorescentlights than the uniormulated polyurethane.

EXAMPLE 7 A stabilized linear polyethylene is prepared by incorporatingtherein 0.5% by Weight of the aluminum complex of di-n-octadecyl esterof ethylenedinitrilotetraacetic acid.

A stabilized polyamide (nylon 6,6) is prepared by incorporating therein0.1% of chromium complex of din-dodecyl ester of ethylene diaminetetraacetic acid.

What is claimed is:

1. A compound of the formula:

o n, 0 ll 1 l R-O -on,-N-on b-0 11 wherein UNITED STATES PATENTS2,859,104 11/1958 Kroll 260429 I 3,051,563 8/1962 Bersworth 260-429 I3,497,535 2/1970 Lennon 260- 482 P DANIEL E. WYMAN, Primary Examiner A.P. DEMERS, Assistant Examiner US. Cl. X.R.

8l72; 260-45.75 R, 45.75 N, 429 J, 429.5, 429.7, 429.9, 438.1, 438.5,446, 448 B, 482 P

